A resistor of 3.6ohms is connected in seris with another of 4.56ohms. What resistance must be placed across 3.6ohms so that total resistance of the circuit shall be 6ohms

Explanation:

Let the resistance placed across the 3.6ohms be x, this means that they are both connected in parallel and then in series to 4.56 ohms;

The equivalent resistance is expressed as;

RT = (1/3.6+1/x) + 4.56

RT = 3.6x/3.6+x + 4.56

Since RT = 6ohms

6 = 3.6x/3.6+x + 4.56

6 - 4.56 = 3.6x/3.6+x

1.44= 3.6x/3.6+x

1.44(3.6+x) = 3.6x

5.184+ 1.44x = 3.6x

5.184 = 3.66x - 1.44x

5.184 = 2.22x

x = 5.184/2.22

x = 2.34  ohms

Hence the resistance that must be placed across 3.6ohms so that total resistance of the circuit shall be 6ohms is 2.34 ohms